Related Experiment Video
Updated: Aug 19, 2026

Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED)
Published on: May 7, 2013
Estrogen increases low voltage-activated calcium current density in GH3 anterior pituitary cells
1Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston 77555.
Abstract:
The effects of estrogen (17 beta-estradiol) on calcium current density were examined in the GH3 anterior pituitary cell line. The addition of 1 nM estrogen to the growth medium induces a 4- to 5-fold increase in low voltage-activated (LVA) Ca2+ current density without affecting high voltage-activated Ca2+ current density. The increase is significant after 24 h, reaches a maximum level in 3 days, and reverses with a similar time course when the estrogen is withdrawn. The EC50 for estrogen stimulation of LVA Ca2+ current density is about 30 pM. The LVA current induced by estrogen has similar voltage dependence and time course of activation, inactivation, and deactivation as controls. The effect of estrogen requires protein synthesis, since it is blocked by cycloheximide. It is suggested that the estrogen-induced increase in LVA Ca2+ current density may be due to an increase in the number of functional channels in the membrane. This effect could be due to insertion of new channels or synthesis of a protein that converts preexisting silent channels into functional channels.
Related Concept Videos
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Secondary Messengers in Hormone Action
Many hormones bind to transmembrane G protein-coupled receptors that connect to regulatory G proteins. These G proteins can then activate enzymes such as adenylyl cyclase or phospholipase C. Adenylyl cyclase converts ATP to cAMP, activating...
Regulation of Hormone Secretion
Humoral stimuli,...

